Allow the target field of a CK_ToUnion to be more easily recovered.

llvm-svn: 310963

1 files changed, 20 insertions, 0 deletions

diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 7dc14183513..7c62ccf052c 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -1695,6 +1695,26 @@ CXXBaseSpecifier **CastExpr::path_buffer() {
   }
 }
 
+const FieldDecl *CastExpr::getTargetFieldForToUnionCast(QualType unionType,
+                                                        QualType opType) {
+  auto RD = unionType->castAs<RecordType>()->getDecl();
+  return getTargetFieldForToUnionCast(RD, opType);
+}
+
+const FieldDecl *CastExpr::getTargetFieldForToUnionCast(const RecordDecl *RD,
+                                                        QualType OpType) {
+  auto &Ctx = RD->getASTContext();
+  RecordDecl::field_iterator Field, FieldEnd;
+  for (Field = RD->field_begin(), FieldEnd = RD->field_end();
+       Field != FieldEnd; ++Field) {
+    if (Ctx.hasSameUnqualifiedType(Field->getType(), OpType) &&
+        !Field->isUnnamedBitfield()) {
+      return *Field;
+    }
+  }
+  return nullptr;
+}
+
 ImplicitCastExpr *ImplicitCastExpr::Create(const ASTContext &C, QualType T,
                                            CastKind Kind, Expr *Operand,
                                            const CXXCastPath *BasePath,